package org.bouncycastle.asn1.x509;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DERBitString;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.DERTaggedObject;

/**
 * The DistributionPoint object.
 * 
 * <pre>
 * DistributionPoint ::= SEQUENCE {
 *      distributionPoint [0] DistributionPointName OPTIONAL,
 *      reasons           [1] ReasonFlags OPTIONAL,
 *      cRLIssuer         [2] GeneralNames OPTIONAL
 * }
 * </pre>
 */
public class DistributionPoint extends ASN1Encodable {
    DistributionPointName distributionPoint;
    ReasonFlags reasons;
    GeneralNames cRLIssuer;

    public static DistributionPoint getInstance(ASN1TaggedObject obj,
            boolean explicit) {
        return getInstance(ASN1Sequence.getInstance(obj, explicit));
    }

    public static DistributionPoint getInstance(Object obj) {
        if (obj == null || obj instanceof DistributionPoint) {
            return (DistributionPoint) obj;
        }

        if (obj instanceof ASN1Sequence) {
            return new DistributionPoint((ASN1Sequence) obj);
        }

        throw new IllegalArgumentException("Invalid DistributionPoint: "
                + obj.getClass().getName());
    }

    public DistributionPoint(ASN1Sequence seq) {
        for (int i = 0; i != seq.size(); i++) {
            ASN1TaggedObject t = ASN1TaggedObject.getInstance(seq
                    .getObjectAt(i));
            switch (t.getTagNo()) {
                case 0:
                    distributionPoint = DistributionPointName.getInstance(t,
                            true);
                    break;
                case 1:
                    reasons = new ReasonFlags(
                            DERBitString.getInstance(t, false));
                    break;
                case 2:
                    cRLIssuer = GeneralNames.getInstance(t, false);
            }
        }
    }

    public DistributionPoint(DistributionPointName distributionPoint,
            ReasonFlags reasons, GeneralNames cRLIssuer) {
        this.distributionPoint = distributionPoint;
        this.reasons = reasons;
        this.cRLIssuer = cRLIssuer;
    }

    public DistributionPointName getDistributionPoint() {
        return distributionPoint;
    }

    public ReasonFlags getReasons() {
        return reasons;
    }

    public GeneralNames getCRLIssuer() {
        return cRLIssuer;
    }

    public DERObject toASN1Object() {
        ASN1EncodableVector v = new ASN1EncodableVector();

        if (distributionPoint != null) {
            //
            // as this is a CHOICE it must be explicitly tagged
            //
            v.add(new DERTaggedObject(0, distributionPoint));
        }

        if (reasons != null) {
            v.add(new DERTaggedObject(false, 1, reasons));
        }

        if (cRLIssuer != null) {
            v.add(new DERTaggedObject(false, 2, cRLIssuer));
        }

        return new DERSequence(v);
    }

    public String toString() {
        String sep = System.getProperty("line.separator");
        StringBuffer buf = new StringBuffer();
        buf.append("DistributionPoint: [");
        buf.append(sep);
        if (distributionPoint != null) {
            appendObject(buf, sep, "distributionPoint",
                    distributionPoint.toString());
        }
        if (reasons != null) {
            appendObject(buf, sep, "reasons", reasons.toString());
        }
        if (cRLIssuer != null) {
            appendObject(buf, sep, "cRLIssuer", cRLIssuer.toString());
        }
        buf.append("]");
        buf.append(sep);
        return buf.toString();
    }

    private void appendObject(StringBuffer buf, String sep, String name,
            String value) {
        String indent = "    ";

        buf.append(indent);
        buf.append(name);
        buf.append(":");
        buf.append(sep);
        buf.append(indent);
        buf.append(indent);
        buf.append(value);
        buf.append(sep);
    }
}
